Patent GB-785229-A (GB)
Title: Improvements in and relating to the production of alkylene oxide polymers
Inventor: STEWART DAVID GORDON
IPC: C08G65/26
Filed: 1955-02-04
Abstract: Alkylene oxide polymers of high molecular weight suitable for use as thickening agents and for processing into thin water-soluble films are obtained by reacting an alkylene oxide, particularly ethylene and propylene oxide, in presence of a catalyst of formula MeRR1x, where Me is a metal of the II or III Groups of the Periodic System, particularly Mg, Al, or Zn, R is a hydrocarbon radical and R1x are x members selected from hydrogen, halogens, hydrocarbon radicals, alkoxy radicals and secondary amino radicals and x is the valency of the metal Me minus one.  Examples of the catalysts are triethyl aluminium, tri-isobutyl aluminium, trioctyl aluminium, di - isobutyl aluminium hydride, diethyl aluminium ethoxide, diethyl aluminium chloride, ethyl aluminium dibutoxide, diethyl piperidyl aluminium and similar magnesium and zinc compounds.  During the polymerization dioxane and the tetramer of ethylene oxide are formed and can be separated by fractionation.  Reaction temperatures of 0-200 DEG  C. and pressures up to 40 atmospheres are employed.  The polymerization may be carried out in presence of solvents, e.g. aliphatic aromatic and chlorinated hydrocarbons or ethers.  In examples: (1) gaseous ethylene oxide is passed into a solution of triethyl aluminium in benzene, the mixture being cooled and maintained at 0 DEG  C. for five days; excess ethylene oxide was distilled off and the polymer precipitated by addition of petroleum ether; (6) liquid ethylene oxide in benzene and diethyl magnesium were heated at 110 DEG  C. for 65 hours; (10) 1,2-propylene oxide in hexane was added dropwise to a solution of triethyl aluminium in hexane; (18) liquid ethylene oxide was added to a solution of tri-iso-butyl aluminium in benzene and heated in an autoclave at 100 DEG  C.  The product was diluted with benzene, unreacted oxide distilled off and the solution added to petroleum ether to precipitate the polymer.  Dioxane was distilled from the filtrate and the residue was distilled to recover the cyclic tetramer.ALSO:The invention comprises the cyclic tetramer of ethylene oxide <FORM:0785229/IV (a)/1> which is obtained along with dioxane and higher polymers by polymerizing ethylene oxide in presence of catalysts of formula MeR.R1x where Me is a metal of Group II or III, R is an hydrocarbon radical and R1x and x members selected from hydrogen, halogens, hydrocarbon radicals, alkoxy radicals and secondary amino radicals, and x is the valency of the metal Me minus one.  Examples of the catalysts are triethyl aluminium, tri-isobutyl aluminium, trioctyl aluminium, di-isobutyl aluminium hydride, diethyl aluminium ethoxide, diethyl aluminium chloride, ethyl aluminium dibutoxide, diethyl piperidyl aluminium, diethyl zinc, ethyl zinc butoxide, diethyl magnesium.  Reaction temperatures from 0-200 DEG C. and pressures up to 40 atmospheres may be employed.  The alkylene oxide, viz. ethylene oxide, is preferably added to a solution of the catalyst in benzene or diethyl ether.  The resulting polymeric material may be treated to remove catalyst therefrom by precipitating the metal (Me) as hydroxide or by extracting the metal as a water-soluble salt by treatment with aqueous acid.  The remaining polymeric material is preferably separated into a lower molecular weight and a higher molecular weight polymer fraction (comprising dioxane and mainly non-cyclic polymer), or the cyclic tetramer of ethylene oxide being recovered from the lower molecular weight polymer fraction.